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help / color / mirror / Atom feedFrom: Andrey V. Lepikhov <[email protected]>
Subject: [PATCH 3/4] GiST-Optimal-WAL-Usage
Date: Mon, 1 Apr 2019 09:07:32 +0500
---
src/backend/access/gist/gist.c | 46 ++++++++++++++++++--------
src/backend/access/gist/gistbuild.c | 32 ++++++++++--------
src/backend/access/gist/gistutil.c | 2 +-
src/backend/access/gist/gistxlog.c | 22 ------------
src/backend/access/rmgrdesc/gistdesc.c | 5 ---
src/include/access/gist_private.h | 7 ++--
src/include/access/gistxlog.h | 1 -
7 files changed, 56 insertions(+), 59 deletions(-)
diff --git a/src/backend/access/gist/gist.c b/src/backend/access/gist/gist.c
index 2fddb23496..0e2b6c3014 100644
--- a/src/backend/access/gist/gist.c
+++ b/src/backend/access/gist/gist.c
@@ -172,7 +172,7 @@ gistinsert(Relation r, Datum *values, bool *isnull,
values, isnull, true /* size is currently bogus */ );
itup->t_tid = *ht_ctid;
- gistdoinsert(r, itup, 0, giststate, heapRel);
+ gistdoinsert(r, itup, 0, giststate, heapRel, false);
/* cleanup */
MemoryContextSwitchTo(oldCxt);
@@ -219,7 +219,8 @@ gistplacetopage(Relation rel, Size freespace, GISTSTATE *giststate,
Buffer leftchildbuf,
List **splitinfo,
bool markfollowright,
- Relation heapRel)
+ Relation heapRel,
+ bool is_build)
{
BlockNumber blkno = BufferGetBlockNumber(buffer);
Page page = BufferGetPage(buffer);
@@ -458,7 +459,7 @@ gistplacetopage(Relation rel, Size freespace, GISTSTATE *giststate,
* insertion for that. NB: The number of pages and data segments
* specified here must match the calculations in gistXLogSplit()!
*/
- if (RelationNeedsWAL(rel))
+ if (RelationNeedsWAL(rel) && !is_build)
XLogEnsureRecordSpace(npage, 1 + npage * 2);
START_CRIT_SECTION();
@@ -479,18 +480,20 @@ gistplacetopage(Relation rel, Size freespace, GISTSTATE *giststate,
PageRestoreTempPage(dist->page, BufferGetPage(dist->buffer));
dist->page = BufferGetPage(dist->buffer);
- /* Write the WAL record */
- if (RelationNeedsWAL(rel))
+ /*
+ * Write the WAL record.
+ * Do not write XLog entry if the insertion is caused by
+ * index build process.
+ */
+ if (RelationNeedsWAL(rel) && !is_build)
recptr = gistXLogSplit(is_leaf,
- dist, oldrlink, oldnsn, leftchildbuf,
- markfollowright);
+ dist, oldrlink, oldnsn, leftchildbuf,
+ markfollowright);
else
recptr = gistGetFakeLSN(rel);
for (ptr = dist; ptr; ptr = ptr->next)
- {
PageSetLSN(ptr->page, recptr);
- }
/*
* Return the new child buffers to the caller.
@@ -544,7 +547,8 @@ gistplacetopage(Relation rel, Size freespace, GISTSTATE *giststate,
if (BufferIsValid(leftchildbuf))
MarkBufferDirty(leftchildbuf);
- if (RelationNeedsWAL(rel))
+
+ if (RelationNeedsWAL(rel) && !is_build)
{
OffsetNumber ndeloffs = 0,
deloffs[1];
@@ -567,6 +571,7 @@ gistplacetopage(Relation rel, Size freespace, GISTSTATE *giststate,
PageSetLSN(page, recptr);
}
+
if (newblkno)
*newblkno = blkno;
}
@@ -583,17 +588,28 @@ gistplacetopage(Relation rel, Size freespace, GISTSTATE *giststate,
* the full page image. There's a chicken-and-egg problem: if we updated
* the child pages first, we wouldn't know the recptr of the WAL record
* we're about to write.
+ *
+ * We use fakeLSNs for inserions caused by index build. And when it is
+ * finished, we write generic_xlog entry for each index page and update
+ * all LSNs. In order to keep NSNs less then LSNs after this update, we
+ * set NSN to InvalidXLogRecPtr, which is the smallest possible NSN.
*/
+
if (BufferIsValid(leftchildbuf))
{
Page leftpg = BufferGetPage(leftchildbuf);
+ XLogRecPtr fakerecptr = InvalidXLogRecPtr;
- GistPageSetNSN(leftpg, recptr);
- GistClearFollowRight(leftpg);
+ if (!is_build)
+ GistPageSetNSN(leftpg, recptr);
+ else
+ GistPageSetNSN(leftpg, fakerecptr);
+ GistClearFollowRight(leftpg);
PageSetLSN(leftpg, recptr);
}
+
END_CRIT_SECTION();
return is_split;
@@ -606,7 +622,7 @@ gistplacetopage(Relation rel, Size freespace, GISTSTATE *giststate,
*/
void
gistdoinsert(Relation r, IndexTuple itup, Size freespace,
- GISTSTATE *giststate, Relation heapRel)
+ GISTSTATE *giststate, Relation heapRel, bool is_build)
{
ItemId iid;
IndexTuple idxtuple;
@@ -619,6 +635,7 @@ gistdoinsert(Relation r, IndexTuple itup, Size freespace,
state.freespace = freespace;
state.r = r;
state.heapRel = heapRel;
+ state.is_build = is_build;
/* Start from the root */
firststack.blkno = GIST_ROOT_BLKNO;
@@ -1251,7 +1268,8 @@ gistinserttuples(GISTInsertState *state, GISTInsertStack *stack,
leftchild,
&splitinfo,
true,
- state->heapRel);
+ state->heapRel,
+ state->is_build);
/*
* Before recursing up in case the page was split, release locks on the
diff --git a/src/backend/access/gist/gistbuild.c b/src/backend/access/gist/gistbuild.c
index 3652fde5bb..8d0d285cab 100644
--- a/src/backend/access/gist/gistbuild.c
+++ b/src/backend/access/gist/gistbuild.c
@@ -17,6 +17,7 @@
#include <math.h>
#include "access/genam.h"
+#include "access/generic_xlog.h"
#include "access/gist_private.h"
#include "access/gistxlog.h"
#include "access/tableam.h"
@@ -181,18 +182,12 @@ gistbuild(Relation heap, Relation index, IndexInfo *indexInfo)
MarkBufferDirty(buffer);
- if (RelationNeedsWAL(index))
- {
- XLogRecPtr recptr;
-
- XLogBeginInsert();
- XLogRegisterBuffer(0, buffer, REGBUF_WILL_INIT);
-
- recptr = XLogInsert(RM_GIST_ID, XLOG_GIST_CREATE_INDEX);
- PageSetLSN(page, recptr);
- }
- else
- PageSetLSN(page, gistGetFakeLSN(heap));
+ /*
+ * Do not write index pages to WAL unitl index build is finished.
+ * But we still need increasing LSNs on each page, so use FakeLSN,
+ * even for relations which eventually need WAL.
+ */
+ PageSetLSN(page, gistGetFakeLSN(heap));
UnlockReleaseBuffer(buffer);
@@ -226,6 +221,15 @@ gistbuild(Relation heap, Relation index, IndexInfo *indexInfo)
freeGISTstate(buildstate.giststate);
+ /*
+ * Create generic wal records for all pages of relation, if necessary.
+ * It seems reasonable not to generate WAL, if we recieved interrupt
+ * signal.
+ */
+ CHECK_FOR_INTERRUPTS();
+ if (RelationNeedsWAL(index))
+ generic_log_relation(index);
+
/*
* Return statistics
*/
@@ -488,7 +492,7 @@ gistBuildCallback(Relation index,
* locked, we call gistdoinsert directly.
*/
gistdoinsert(index, itup, buildstate->freespace,
- buildstate->giststate, buildstate->heaprel);
+ buildstate->giststate, buildstate->heaprel, true);
}
/* Update tuple count and total size. */
@@ -695,7 +699,7 @@ gistbufferinginserttuples(GISTBuildState *buildstate, Buffer buffer, int level,
InvalidBuffer,
&splitinfo,
false,
- buildstate->heaprel);
+ buildstate->heaprel, true);
/*
* If this is a root split, update the root path item kept in memory. This
diff --git a/src/backend/access/gist/gistutil.c b/src/backend/access/gist/gistutil.c
index 2163cc482d..af278e5ded 100644
--- a/src/backend/access/gist/gistutil.c
+++ b/src/backend/access/gist/gistutil.c
@@ -1004,6 +1004,7 @@ gistproperty(Oid index_oid, int attno,
* Temporary and unlogged GiST indexes are not WAL-logged, but we need LSNs
* to detect concurrent page splits anyway. This function provides a fake
* sequence of LSNs for that purpose.
+ * Persistent relations are also not WAL-logged while we build index.
*/
XLogRecPtr
gistGetFakeLSN(Relation rel)
@@ -1024,7 +1025,6 @@ gistGetFakeLSN(Relation rel)
* Unlogged relations are accessible from other backends, and survive
* (clean) restarts. GetFakeLSNForUnloggedRel() handles that for us.
*/
- Assert(rel->rd_rel->relpersistence == RELPERSISTENCE_UNLOGGED);
return GetFakeLSNForUnloggedRel();
}
}
diff --git a/src/backend/access/gist/gistxlog.c b/src/backend/access/gist/gistxlog.c
index cb80ab00cd..4fb1855e89 100644
--- a/src/backend/access/gist/gistxlog.c
+++ b/src/backend/access/gist/gistxlog.c
@@ -490,25 +490,6 @@ gistRedoPageSplitRecord(XLogReaderState *record)
UnlockReleaseBuffer(firstbuffer);
}
-static void
-gistRedoCreateIndex(XLogReaderState *record)
-{
- XLogRecPtr lsn = record->EndRecPtr;
- Buffer buffer;
- Page page;
-
- buffer = XLogInitBufferForRedo(record, 0);
- Assert(BufferGetBlockNumber(buffer) == GIST_ROOT_BLKNO);
- page = (Page) BufferGetPage(buffer);
-
- GISTInitBuffer(buffer, F_LEAF);
-
- PageSetLSN(page, lsn);
-
- MarkBufferDirty(buffer);
- UnlockReleaseBuffer(buffer);
-}
-
/* redo page deletion */
static void
gistRedoPageDelete(XLogReaderState *record)
@@ -594,9 +575,6 @@ gist_redo(XLogReaderState *record)
case XLOG_GIST_PAGE_SPLIT:
gistRedoPageSplitRecord(record);
break;
- case XLOG_GIST_CREATE_INDEX:
- gistRedoCreateIndex(record);
- break;
case XLOG_GIST_PAGE_DELETE:
gistRedoPageDelete(record);
break;
diff --git a/src/backend/access/rmgrdesc/gistdesc.c b/src/backend/access/rmgrdesc/gistdesc.c
index 3ff4f83d38..eb308c72d6 100644
--- a/src/backend/access/rmgrdesc/gistdesc.c
+++ b/src/backend/access/rmgrdesc/gistdesc.c
@@ -71,8 +71,6 @@ gist_desc(StringInfo buf, XLogReaderState *record)
case XLOG_GIST_PAGE_SPLIT:
out_gistxlogPageSplit(buf, (gistxlogPageSplit *) rec);
break;
- case XLOG_GIST_CREATE_INDEX:
- break;
case XLOG_GIST_PAGE_DELETE:
out_gistxlogPageDelete(buf, (gistxlogPageDelete *) rec);
break;
@@ -98,9 +96,6 @@ gist_identify(uint8 info)
case XLOG_GIST_PAGE_SPLIT:
id = "PAGE_SPLIT";
break;
- case XLOG_GIST_CREATE_INDEX:
- id = "CREATE_INDEX";
- break;
case XLOG_GIST_PAGE_DELETE:
id = "PAGE_DELETE";
break;
diff --git a/src/include/access/gist_private.h b/src/include/access/gist_private.h
index 02dc285a78..78e2e3fb31 100644
--- a/src/include/access/gist_private.h
+++ b/src/include/access/gist_private.h
@@ -244,6 +244,7 @@ typedef struct
Relation r;
Relation heapRel;
Size freespace; /* free space to be left */
+ bool is_build;
GISTInsertStack *stack;
} GISTInsertState;
@@ -393,7 +394,8 @@ extern void gistdoinsert(Relation r,
IndexTuple itup,
Size freespace,
GISTSTATE *GISTstate,
- Relation heapRel);
+ Relation heapRel,
+ bool is_build);
/* A List of these is returned from gistplacetopage() in *splitinfo */
typedef struct
@@ -409,7 +411,8 @@ extern bool gistplacetopage(Relation rel, Size freespace, GISTSTATE *giststate,
Buffer leftchildbuf,
List **splitinfo,
bool markleftchild,
- Relation heapRel);
+ Relation heapRel,
+ bool is_build);
extern SplitedPageLayout *gistSplit(Relation r, Page page, IndexTuple *itup,
int len, GISTSTATE *giststate);
diff --git a/src/include/access/gistxlog.h b/src/include/access/gistxlog.h
index 2f87b67a53..80931497ca 100644
--- a/src/include/access/gistxlog.h
+++ b/src/include/access/gistxlog.h
@@ -23,7 +23,6 @@
* FSM */
#define XLOG_GIST_PAGE_SPLIT 0x30
/* #define XLOG_GIST_INSERT_COMPLETE 0x40 */ /* not used anymore */
-#define XLOG_GIST_CREATE_INDEX 0x50
#define XLOG_GIST_PAGE_DELETE 0x60
/*
--
2.17.1
--------------5B85550EC82B346D9FBFC34E
Content-Type: text/x-patch;
name="v2_0004-SP-GiST-Optimal-WAL-Usage.patch"
Content-Transfer-Encoding: 7bit
Content-Disposition: attachment;
filename="v2_0004-SP-GiST-Optimal-WAL-Usage.patch"
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